The present invention relates generally to surface mount technology, and more specifically to non-solder solutions for surface mount technology.
A problem with conventional surface mount technology (SMT) is reflowing solder on a board or other circuit carrier to perform a surface mount connection. During reflow, the board solder, used for attaching the circuit board carrier to a surface mount assembly, is melted. Traditional solder melts at a temperature of approximately 183 degrees Centigrade. Other melt temperatures may be used, but a temperature higher than ambient temperature must be used to reflow solder. The reflowing process requires special equipment to generate the heat required to melt the board solder.
Additionally, personal computer manufacturers, who assemble computers from various parts, must generally keep parts stock on hand for assembly of computers. These personal computer manufacturers typically use a specific mounting process to mount chip cartridges to their own boards. Any cartridges or SMT technologies that are incompatible with the SMT used by the specific manufacturer will be disfavored by that manufacturer, as it can be quite expensive to change SMT strategies. Also, manufacturers of sockets and cartridges must currently manufacture parts capable of being used with specific SMT strategies. This results in increased production costs, as different lines and manufacturing processes must be used to manufacture different cartridge solutions.
For example, various packages for processors are currently used, and the type used depends on the specific user of the processor. For manufacturers that desire a component solution to supply only a processor instead of a processor package or cartridge, a narrow height socketable solution is desirable. Present technology uses a socket solution having an organic land grid substrate with a pin grid array interposer attached by SMT process. Pins are attached after that process. The total height of such a package is high. Customers desiring a processor only package do not want such a high height, and typically desire a processor package that is smaller in height than conventional processors.
Manufacturers using or desiring a cartridge type processor package want a socketable solution, and often are not concerned with the total height of the cartridge. However, such manufacturers are concerned with the available SMT processes available for use with the cartridge.
Variations in and warpage of substrates and boards decrease tolerance of conventional SMT to any inconsistencies and differences between parts. This can lead to decreased yield and manufacturability of sockets and boards, as well as poor or reduced performance and reliability. Problems may occur in creating a good electrical contact between a socket and a board. Further, stresses placed on the assembled board during use and installation may also contribute to a weakening of the contact between a socket and a board.
Also, problems exist with increasing the amount of pressure required to mount a processor in a socketable solution. To get a good electrical contact, a certain amount of force must be applied to the processor. This force is typically stated as a force per pin. As the amount of force per pin increases, it becomes increasingly more difficult to mount processors in a socketable solution by hand. As more machinery is required, assembly costs and complexity of assembly increase.
Thermal transfer of generated heat from a processor has been accomplished within the microprocessor and computer industry by using a metal cover for the processor package or cartridge. This cover fits over and around the processor or cartridge to dissipate heat from the processor.
A mounting socket embodying the invention includes a socket body having a first side and a second, opposite side, the body having a number of vias or through holes, and a number of conductive terminals within the vias. The terminals are made from an elastically deformable member.
In another embodiment, a mounting socket has a substrate with vias or through holes in the substrate, and conductive terminals within the substrate. An adhesive layer is applied to the board side of the socket to attach the socket to a circuit or motherboard. Another adhesive layer is applied to the opposite side of the socket for attachment of the socket to a processor.
A method of mounting a socket to a board includes applying an adhesive layer to a board side of the socket, leveling the adhesive layer to make the adhesive layer substantially coplanar with contact terminals of the socket so as to avoid the adhesive interfering with the electrical contact between the terminals and the board, and adhering the socket to the board.